Feed additive prepared by using agar production waste residue as carrier and application of feed additive

Abstract

The invention belongs to the technical field of feed, and discloses a feed additive prepared by using agar production waste residue as a carrier and application of the feed additive, and per kilogram of the feed additive comprises 50-150g of olive leaf extract, 50-150g of flaxseed gum, 50-200g of bile salt, 50-200g of silkworm excrement and 300-800g of agar production waste residue. The feed additive disclosed by the invention can effectively promote ingestion and growth of fish and blue crabs, improve the antioxidant capacity of organisms, reduce lipid deposition of livers and maintain the health of the livers and intestinal tracts.

Description

Technical Field

[0001] The invention relates to the field of fish feed, and in particular to a feed additive prepared by using agar production waste residue as a carrier and application thereof. Background Art

[0002] In recent years, due to the influence of climate, the fluctuation of global fish meal resources has led to a significant increase in its price fluctuations. In order to reduce the cost of aquaculture feed, other terrestrial animal and plant proteins are often used to partially or completely replace fish meal in large-scale economic fish farming. However, due to the generally unbalanced amino acid composition of other terrestrial animal proteins, the common presence of anti-nutritional factors in plant proteins, poor palatability and other shortcomings, the use of other animal and plant proteins to replace fish meal can easily lead to problems such as decreased growth performance of aquatic animals, decreased lipid and protein metabolism, oxidative stress, intestinal structural damage and dysbacteriosis, and decreased intestinal immunity.

[0003] Gracilaria is a typical representative of Gracilaria seaweed. With a high agar content of 20-30%, it is the best quality raw material for agar production in Gracilaria and has become the main raw material for agar extraction in my country (accounting for more than 80%). At present, agar extraction is mainly based on alkali extraction process. After agar is extracted from Gracilaria by acid-base treatment and boiling, the residue is filtered out with expanded perlite filter aid to finally obtain agar with high purity. For every ton of agar produced, up to 10-15 tons of industrial waste residue (water content 60-80%) with perlite filter aid as carrier can be generated. At present, the main treatment method of the waste residue is to directly pile it up in flower gardens or orchards free of charge. Appropriate stacking is beneficial to flower gardens, but too much waste rich in organic matter and nutrients will pollute the environment, occupy a large amount of land and waste resources. According to biological and nutritional analysis, it is found that the waste residue after agar extraction is not only rich in carbohydrates and minerals such as calcium, iron, zinc, and manganese, but also contains a large amount of seaweed polysaccharides and a small amount of phycoerythrin and other active substances. In addition, it also has the adsorption performance of perlite filter aid. However, there is a lack of research and development of recycling technology for it. The current waste residue treatment method not only wastes manpower, material and financial resources, but also causes environmental pollution and waste of beneficial resources. If it can be used comprehensively and turned into treasure, it will not only reduce the pollution and land occupation of waste residues, save the transportation and treatment costs of waste residues, but also bring huge economic benefits to the company, which is in line with the national circular economy industry policy, and can increase local profits and taxes and provide jobs. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a feed additive using agar production waste as a carrier, in combination with the above feed application status of aquaculture industry, that is, according to the physicochemical and nutritional properties of agar production waste, other functional active substances are used in combination to prepare a feed additive with the functions of promoting the growth of aquaculture animals and improving the body's antioxidant and immune functions.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A feed additive prepared by using waste residue from agar production as a carrier comprises olive leaf extract, flaxseed gum, bile acid salt, silkworm excrement and waste residue from agar production.

[0007] Each kilogram of the feed additive comprises 50-150g of olive leaf extract, 50-150g of flaxseed gum, 50-200g of bile acid salt, 50-200g of silkworm excrement and 300-800g of agar production waste residue.

[0008] The present invention has been found through research that when the feed additive is prepared by using 50-150g of olive leaf extract, 50-150g of flaxseed gum, 50-200g of bile acid salt, 50-200g of silkworm excrement and 300-800g of agar production waste residue per kilogram, the growth performance and antioxidant capacity of tilapia and blue crab can be significantly improved, the liver and intestinal health can be maintained, the feed production cost can be reduced, and the breeding efficiency can be improved.

[0009] Preferably, the mass ratio of the olive leaf extract, the flaxseed gum, the bile salt, the silkworm excrement, and the agar production waste residue comprises 5-15:5-15:5-20:5-20:30-80.

[0010] Preferably, the mass ratio of the olive leaf extract, the flaxseed gum, the bile salt, the silkworm excrement, and the agar production waste residue comprises 10:10:15:15:50.

[0011] Preferably, the mass ratio of the olive leaf extract, the flaxseed gum, the bile salt, the silkworm excrement, and the agar production waste residue comprises 5:5:10:20:60.

[0012] Preferably, the olive leaf extract includes one or more of olive leaf water extract and olive leaf alcohol extract; the silkworm litter includes excrement of silkworms fed with one or more of soybean meal, mulberry leaf powder and corn; and the agar production waste contains one or more of minerals, seaweed polysaccharides and seaweed fibers.

[0013] Preferably, the olive leaf extract is a water extract or an alcohol extract with a purity of 10 to 30%, which can be obtained through conventional commercial channels.

[0014] Preferably, the silkworm litter is a kind of excrement of silkworms, and the feed fed to the silkworms is made by mixing 60-70% by weight of soybean meal, 10-20% by weight of mulberry leaf powder and 15-25% by weight of corn flour with water.

[0015] Preferably, the agar production waste residue is waste residue formed during the industrial extraction of agar from the seaweed Gracilaria lemaneiformis or Gelidium amansoniae, and contains 30-40% by mass of minerals, 10-20% of seaweed polysaccharides, and 5-10% of seaweed fibers.

[0016] A method for preparing the feed additive using agar production waste residue as a carrier comprises:

[0017] A. Drying, crushing and sieving the agar production waste residue and the silkworm excrement to obtain agar production waste residue powder particles and silkworm excrement powder particles respectively;

[0018] B. Using the agar production waste residue powder particles as a carrier, the olive leaf extract, the flaxseed gum, the bile acid salt, and the silkworm excrement powder particles are mixed in to obtain the feed additive prepared using the agar production waste residue as a carrier.

[0019] Preferably, in step A, the drying comprises drying at 65-80° C. to a moisture content of ≤8%; the pulverizing comprises pulverizing to a particle size of 50-250 μm; and the screening comprises screening through a 60-mesh sieve.

[0020] An application of the feed additive prepared using agar production waste residue as a carrier is used to prepare one or more preparations including promoting fish growth, promoting crab growth, improving liver health, improving intestinal health, reducing feed conversion, reducing costs, and improving breeding benefits.

[0021] The feed additive is added to the basic feed, or directly sprinkled into the pond as an animal health product.

[0022] Preferably, the preparation includes feed; in the feed, the feed additive prepared using agar production waste residue as a carrier is added in an amount of 1 to 5% by mass.

[0023] Preferably, the preparation includes a health product; the amount of the health product added when sprayed in the pond is 1-5 kg / mu.

[0024] The implementation of the present invention has the following beneficial effects:

[0025] The invention aims at the resource waste and environmental pollution problems existing in the waste residue of agar production at present. Freshwater omnivorous tilapia and seawater omnivorous mud crab are used as experimental objects. An additive prepared by compounding silkworm litter, bile acid salt, olive leaf extract and flaxseed gum in proportion is added to the compound feed of fry of tilapia and mud crab. The waste residue of agar extraction contains up to 10-20% of seaweed polysaccharide, 5-10% of seaweed dietary fiber, 4-6% of seaweed protein and 30-40% of crude ash. Since seaweed Gracilaria or Gelidium amansii is subjected to alkali boiling treatment during the agar extraction process, most of the acidic heteropolysaccharides are degraded into oligosaccharides or monosaccharides. These polysaccharide degradation products have been confirmed to have multiple biological functions such as anti-oxidation, anti-virus, anti-tumor and anti-aging. The protein in Gracilaria is mainly phycobiliprotein, which has good effects of anti-deformation, scavenging free radicals, improving immunity and inhibiting tumor cell growth. Silkworm litter contains about 0.5-1% chlorophyll, 5-10% low-methoxy pectin, 0.3-1.5% 1-deoxynojirimycin (DNJ) and other precious active ingredients, which have the effects of improving insulin sensitivity, lowering blood sugar and blood lipids, improving and treating anemia, scavenging free radicals, anti-oxidation, anti-inflammatory, and anti-cancer. The phenolic substances contained in olive leaf extract are mainly oleuropein, which has strong free radical scavenging, anti-oxidation, anti-inflammatory and antibacterial effects, and also has the effects of reducing body fat and blood lipids and treating diabetes, hypertension and atherosclerosis; flaxseed gum is a water-soluble polysaccharide with certain antioxidant and antibacterial abilities, as well as good blood sugar and blood lipid lowering, treating diabetes and arteriosclerosis; and bile acid has the functions of emulsifying fat in the animal body, improving the body's absorption and utilization of fat, promoting the absorption of fat-soluble vitamins, regulating liver function, preventing the formation of cholesterol stones, and protecting the gastrointestinal tract. The breeding experiments on tilapia fry and blue crab fry have proved that the feed additive provided by the present invention can significantly improve the growth of cultured tilapia fry and blue crab fry, effectively enhance their antioxidant and immune abilities, reduce the incidence of liver fat deposition and fatty liver, and reduce the feed conversion rate and feed cost, improve the economic benefits of breeding, and is conducive to the healthy development of intensive breeding of aquatic animals, and has very important practical application value.

[0026] The invention discloses a feed additive prepared by using agar production waste residue as a carrier and its application. The feed additive comprises 50-150g of olive leaf extract, 50-150g of linseed gum, 50-200g of bile acid salt, 50-200g of silkworm excrement and 300-800g of agar production waste residue per kilogram. The feed additive of the invention can effectively promote the feeding and growth of fish and blue crabs, improve the body's antioxidant capacity, reduce lipid deposition in the liver, and maintain the health of the liver and intestines. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the effect of the example feed with different addition levels of the composite additive on the liver HE slices of tilapia fry; wherein, C0 is the control group; C1 is the composite additive 1% group; C2 is the composite additive 2% group.

[0028] Figure 2 Schematic diagram of the effect of feed with different addition levels of the composite additive on the level of intestinal flora of juvenile mud crabs; wherein D0 is the control group of fresh blue clams; D1 is the composite additive 1% group; and D2 is the composite additive 2% group. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] Unless otherwise specified, the raw materials, reagents or devices used in the following examples or comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0032] Agar production waste was provided by Guangdong Haizhen Seaweed Biotechnology Co., Ltd.

[0033] Silkworm excrement was provided by Zou Lu Chinese Medicine Research Institute (Guangzhou) Co., Ltd.

[0034] Example 1

[0035] First, the present invention evaluates whether simply adding agar production waste residue to feed has an impact on the growth and health of fish. Taking tilapia fry compound feed added with 1-7% agar production waste residue as an example, the present invention comprises the following steps:

[0036] First, 1.5 kg of fish meal, 20 kg of soybean meal, 4 kg of cottonseed meal, 2.5 kg of corn DDGS, 3 kg of α-starch, and 7.25 kg of corn starch are crushed and mixed to obtain mixed material 1, and then 0.5 kg of premixed complex minerals, 0.5 kg of premixed complex vitamins, 0.225 kg of sodium chloride, 0.025 kg of yttrium oxide, 0.25 kg of choline chloride and 0.75 kg of monocalcium phosphate are mixed and added to mixed material 1 and stirred to obtain mixed material 2, and then 2 kg of soybean oil is added to the mixture and mixed in a blender to obtain mixed material 3. Then, material 3 is divided into 5 equal parts, and 0, 0.5, 1.5, 2.5, and 3.5 kg of agar production waste residue are added at a percentage of 0, 1, 3, 5, and 7%, and 7.5, 7.0, 6.0, 5.0, and 4.0 kg of wheat bran are used to balance the mass of each group to 10 kg, and then they are placed in a mixer for stirring, and 25-35% of water is added and stirred evenly, and then a feed expander is used to press and form particles with a particle size of 2 mm. Finally, the mixture is air-dried to obtain compound feeds containing 0%, 1%, 3%, 5%, and 7% of agar production waste residue, respectively, and are named feeds A0, A1, A2, A3, and A4, respectively.

[0037] The breeding experiment was conducted in the indoor circulating water system of the College of Science, Shantou University, Guangdong. Nile tilapia fry were purchased from a fish fry farm in Jieyang City, Guangdong Province. After the experimental fry were temporarily raised for 2 weeks, 300 fish of uniform size and health were randomly selected for grouping. Each group had 3 tanks, and each tank had 20 fish. They were fed twice at 8:30 and 17:30 according to the total daily feed amount of 3-6% of their body weight. The water temperature was recorded regularly every day, and dead fish were fished out in time. During the experiment, the circulating water system was turned on and circulated uninterruptedly. The water was changed every two days, and the water change volume was 1 / 3 of the total water volume; the water temperature was 28℃-30℃; the ammonia nitrogen concentration was <0.05mg / L, and the dissolved oxygen was ≥5mg / L. The breeding cycle was 6 weeks in total. After the breeding experiment, all the experimental fish were fasted for 24 hours and anesthetized in seawater containing 0.01% 2-phenoxyethanol. The surface moisture of the fish was wiped with a semi-dry towel, and the weight and body length of each fish were measured to calculate the growth performance index. The test results are shown in Table 1.

[0038] Table 1

[0039]

[0040] Note: In Table 1, data are mean ± standard error (n = 3). Different superscript letters in the same row indicate significant differences (P < 0.05).

[0041] From the growth index results in Table 1, it can be seen that adding 1-3% agar production waste residue to the feed will not have a significant impact on the health and survival of the fish, nor will it cause excessive accumulation of abdominal fat. Instead, it can promote the growth of the fish. The final weight and weight gain rate of the fish body are significantly improved compared with the control group A0. The weight gain rates of the A1 and A2 groups increased by 2.82% and 10.27% respectively, while the feed coefficient decreased by 7.09% and 13.39%. However, when the amount of waste residue added is increased to more than 5% (A3, A4), the final weight and weight gain rate of the fish body show a downward trend, while the feed coefficient shows an upward trend. The above results show that adding 1-3% agar production waste residue to the feed will not only have no significant impact on the health and survival of the fish, but also promote the growth of the fish, reduce feed costs, and improve breeding benefits.

[0042] Example 2

[0043] According to the above results, in order to better carry out comprehensive utilization of waste residues, the present invention combines its physical, chemical and nutritional properties, uses other functional active substances in combination, develops a feed additive with functions such as promoting the growth of aquatic animals and improving the body's antioxidant capacity, and conducts breeding experiments on tilapia and mud crab for evaluation, specifically comprising the following steps:

[0044] First, the present invention is based on the waste residue of agar production, and olive leaf extract, linseed gum, bile acid salt and silkworm sand in different proportions are matched, crushed and mixed evenly, and 4 kinds of feed additives are obtained. In addition, wheat bran is used as a carrier, and the same active ingredient is matched, and the obtained 1 kind of feed additive is a control group. The specific proportions of 5 kinds of additive complexes are shown in Table 2. Then according to the feed preparation method of Example 1, 100 grams of chicken meal, 350 grams of soybean meal, 60 grams of corn protein, 120 grams of wheat bran, 156 grams of flour, 140 grams of cassava starch, 5 grams of sodium chloride, 5 grams of calcium dihydrogen phosphate, 2 grams of aquatic multivitamin, 2 grams of multi-mineral, 10 grams of soybean lecithin, 40 grams of soybean oil and 10 grams of additive complex are added to each kilogram of feed, and a feed extruder is used to press and form particles with a particle size of 2 mm, and air-dried in the sun to obtain 4 groups of feeds, which are named B0 (control group), B1, B2, B3, and B4. Then, the tilapia aquaculture test effect evaluation was carried out according to the aquaculture test method of Example 1. The aquaculture period was 4 weeks. The results are shown in Table 3.

[0045] Table 2

[0046]

[0047] Table 3

[0048]

[0049] Note: In Table 3, data are mean ± standard error (n = 3). Different superscript letters in the same row indicate significant differences (P < 0.05).

[0050] From the growth index results in Table 3, it can be seen that adding a feed additive with agar production waste as a carrier can significantly improve the growth of tilapia, especially when the ratio of 50g olive leaf extract, 50g linseed gum, 100g bile acid salt, 200g silkworm excrement and 600g agar production waste (B2), or the ratio of 100g olive leaf extract, 100 linseed gum, 150g bile acid salt, 150g silkworm excrement and 500g agar production waste (B4) is used to make per kilogram of feed additive, compared with the composite additive (B0) with wheat bran as a carrier, it can significantly improve the growth performance of tilapia, and its weight gain rate is increased by 18.36% and 19.6% respectively compared with the control group, while also reducing the feed coefficient and feed generation cost, thereby improving the breeding efficiency.

[0051] Example 3

[0052] Secondly, the present invention prepared 1 kg of composite additive according to the preferred feed additive formula (B4 group) in Example 2, and added it to the basic feed at a ratio of 0%, 1%, and 2%. According to the method of Example 1, three groups of tilapia compound feeds were prepared, which were named C0, C1, and C2 respectively. The specific formula is shown in Table 4. Then, according to the breeding test method of Example 1, the tilapia breeding test effect evaluation was carried out, and the breeding cycle was 4 weeks. The results are shown in Tables 5, 6 and Figure 1 shown.

[0053] Table 4

[0054]

[0055] Table 5

[0056]

[0057] Note: In Table 5, data are mean ± standard error (n = 3). Different superscript letters in the same row indicate significant differences (P < 0.05).

[0058] Table 6

[0059]

[0060] Note: In Table 6, data are mean ± standard error (n = 3). Different superscript letters in the same row indicate significant differences (P < 0.05).

[0061] From the growth index of Table 5, it can be seen that the addition of the preferred feed additive (containing 100g olive leaf extract, 100g linseed gum, 150g bile acid salt, 150g silkworm excrement and 500g agar production waste residue per kilogram of composite additive) in the feed significantly promoted the growth of tilapia, and the weight gain rate increased more significantly when the additive was added in an amount of 2%. Compared with the control group, when 1% or 2% of the functional additive prepared by agar production waste residue as a carrier was added to the feed, the weight gain rate increased by 20.4% to 25.6%. At the same time, the feed coefficient of tilapia was significantly reduced after adding the functional additive. Compared with the control group, the feed coefficient was reduced by 16.4% to 21.2%, which greatly reduced the breeding cost and improved the breeding efficiency. In addition, from Table 6, it can be seen that the addition of the functional additive prepared by agar production waste residue as a carrier in the feed can reduce the content of serum triglycerides and reduce the content of peroxidation product malondialdehyde in serum, and the reduction is particularly significant when the addition amount is 2%. Adding the composite additive to the feed also improves the total antioxidant capacity of the fish, the activity of acid phosphatase and alkaline phosphatase. The results of HE sections of the liver show that adding the composite additive to the feed can reduce the degree of cavitation of liver tissue and alleviate excessive lipid deposition in the liver ( Figure 1 ).

[0062] Example 4

[0063] Finally, the present invention prepared 1 kg of composite additives according to the preferred feed additive formula (B4 group) in Example 2, and added it to the basic feed of mud crabs at a ratio of 1% and 2%, and prepared 2 groups of soft granular feeds according to the method of patent ZL202210414933.X, which were named D1 and D2 respectively. The specific formulas are shown in Table 7. A control group D0 was set up to feed fresh iced blue clams. Then, a blue crab breeding experiment was carried out in a crab apartment. The experiment was divided into three groups, each with 3 replicates and 15 crabs in each replicate. The breeding cycle was 6 weeks, and the results are shown in Tables 8, 9 and Figure 2 shown.

[0064] Table 7

[0065]

[0066] Table 8

[0067]

[0068] Note: In Table 8, data are mean ± standard error (n = 3). Different superscript letters in the same row indicate significant differences (P < 0.05).

[0069] Table 9

[0070]

[0071] Note: All values ​​are expressed as mean ± standard error (n = 3). Superscript letters in the same row indicate significant differences between the experimental groups (a>b). Different superscript letters in the same row indicate significant differences (P < 0.05).

[0072] As can be seen from Table 8, adding the preferred feed additive (containing 100g olive leaf extract, 100g flaxseed gum, 150g bile salt, 150g silkworm litter and 500g agar production waste residue per kilogram of composite additive) to the feed significantly promoted the molting and growth of the mud crab, and the weight gain rate and molting rate increased more significantly when the additive was added at a 2% dosage. Compared with the control group, when 2% of the functional additive prepared with agar production waste residue as a carrier was added to the feed, the weight gain rate and molting rate increased by 58.02% and 59.99%, respectively. In addition, through high-throughput analysis of 16s rDNA of the intestinal flora of the mud crab, it was found that the addition of the composite additive to the feed significantly increased the diversity of the intestinal flora, such as the α diversity index, including the Shannon index, Simpson index, Chao1 and ACE index were all higher than the control group (Table 9); Figure 2 It can be seen that the addition of the composite additive significantly reduced the level of pathogenic bacteria Proteobacteria, while significantly increased the levels of beneficial bacteria Firmicutes and Bacteroidetes. This shows that the composite additive helps to improve the intestinal health of blue crabs.

[0073] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A feed additive prepared by using agar production waste residue as a carrier, characterized in that: Including olive leaf extract, flaxseed gum, bile salts, silkworm feces, and agar production waste.

2. The feed additive prepared by using agar production waste residue as a carrier according to claim 1, characterized in that: The mass ratio of the olive leaf extract, the flaxseed gum, the bile salt, the silkworm excrement and the agar production waste residue is 5-15:5-15:5-20:5-20:30-80.

3. The feed additive prepared by using agar production waste residue as a carrier according to claim 1, characterized in that: The mass ratio of the olive leaf extract, the flaxseed gum, the bile salt, the silkworm excrement, and the agar production waste residue is 10:10:15:15:

50.

4. The feed additive prepared by using agar production waste residue as a carrier according to claim 1, characterized in that: The mass ratios of the olive leaf extract, the flaxseed gum, the bile salt, the silkworm excrement, and the agar production waste residue include 5:5:10:20:

60.

5. The feed additive prepared by using agar production waste residue as a carrier according to claim 1, characterized in that: The olive leaf extract comprises one or more of olive leaf water extract and olive leaf alcohol extract; the silkworm litter comprises excrement of silkworms fed with one or more of soybean meal, mulberry leaf powder and corn powder; the agar production waste residue contains one or more of minerals, seaweed polysaccharides and seaweed fibers.

6. A method for preparing a feed additive using agar production waste residue as a carrier according to claim 1, characterized in that: include: A. Drying, crushing and sieving the agar production waste residue and the silkworm excrement to obtain agar production waste residue powder particles and silkworm excrement powder particles respectively; B. Using the agar production waste residue powder particles as a carrier, the olive leaf extract, the flaxseed gum, the bile acid salt, and the silkworm excrement powder particles are mixed in to obtain the feed additive prepared using the agar production waste residue as a carrier.

7. The preparation method according to claim 6, characterized in that: In step A, the drying comprises drying at 65-80° C. to a moisture content of ≤8%; the pulverizing comprises pulverizing to a particle size of 50-250 μm; and the screening comprises screening through a 60-mesh sieve.

8. An application of the feed additive prepared by using agar production waste residue as a carrier according to claim 1, characterized in that: Used to prepare one or more preparations including promoting fish growth, promoting crab growth, improving fish liver health, improving intestinal health, reducing feed conversion rate, reducing costs, and improving breeding benefits.

9. The use according to claim 6, characterized in that: The preparation comprises feed; in the feed, the feed additive prepared by using agar production waste residue as a carrier is added in an amount of 1-5% by mass.

10. The use according to claim 6, characterized in that: The preparation includes health products; the amount of the health products added when sprayed in the pond includes 1-5 kg / mu.

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